“the son of nobles.” This is an idiom and means “of noble character,” the sons having the character of the father. It does not mean that the king would literally be a son of a nobleman, although he might be. Similarly, a “son of light” is a godly person while a “son of darkness” is an ungodly person, and a “son of Satan” has the characteristics of Satan.

“in due season.” That is, at the proper time (cp. Ecc. 3:1).